The present invention relates to a digital video tape recorder and, more particularly, to apparatus for recording a digital video signal which allows for the simultaneous monitoring of an input analog video signal or an input digital video signal which is digitally recorded on a record medium.
Analog video tape recorders are known to record analog video signals on a magnetic tape in analog form and to provide the video signal as an output signal so that the analog video signal may be monitored, e.g., viewed on a television monitor.
Digital video tape recorders are known to convert an analog video signal into a digital video signal and then to record the digital video signal on a magnetic tape. The recording and reproduction of digital video signals is more advantageous than the recording and reproduction of analog video signals because the picture quality of the reproduced digital video signal will not deteriorate through multiple dubbings. Moreover, error correction by way of digital processing further minimizes errors in recorded and reproduced digital video signals. However, the monitoring of digital video signals while they are being recorded cannot be accomplished merely by supplying the digital video signal to an output terminal. Digital video signals generally are transmitted on a digital serial interface line admitting of one data format while analog video signals admit of a second data format.
Further, a video signal to be recorded in digital form may be supplied as either a digital video signal or as an analog video signal whose formats, even after the analog signal is converted to digital form, are not the same. Current digital video tape recorders do not include the capability of recording video signals admitting of both of the above-mentioned data formats while providing an output signal that allows a user to monitor the video signals being recorded.
Therefore, it is an object of the present invention to provide apparatus for recording a digital video signal on a record medium which overcomes the shortcomings of prior art devices.
Another object of the present invention is to provide recording apparatus which also provides the digital video signal that is being recorded as an output signal so as to allow a user to monitor that digital video signal.
A further object of the present invention is to provide recording apparatus which is capable of recording a digital video signal supplied thereto as an analog video signal while simultaneously supplying on a digital interface line the signal being recorded.
An additional object of this invention is to provide recording apparatus which is capable of recording a digital video signal supplied thereto as a digital signal via a digital interface and simultaneously supplying an analog video signal as an output which corresponds to the digital video signal being recorded.
Various other objects, advantages and features of the present invention will become readily apparent to those of ordinary skill in the art, and the novel features will be particularly pointed out in the appended claims.
In accordance with one embodiment of the present invention, apparatus is provided for receiving (e.g., on a digital serial interface transmission line) a digital video signal, producing a recordable digital video signal from the digital video signal, recording the recordable digital video signal on a record medium, converting the received digital video signal to an analog video signal and supplying the analog video signal as an output simultaneously with the recording of the recordable digital video signal.
In accordance with another embodiment of the present invention, apparatus is provided for receiving a digital video signal, detecting errors in the digital video signal, adding to the digital video signal error flags identifying respective detected errors, correcting the detected errors in the digital video signal in response to the added error flags to produce a corrected digital video signal, encoding the corrected digital video signal to provide a recordable digital video signal, recording the recordable digital video signal on a record medium, decompressing the digital video signal to provide a decompressed digital video signal, converting the decompressed digital video signal to an analog video signal and supplying the analog video signal as an output simultaneously with the recording of the recordable digital video signal.
In accordance with a further embodiment of the present invention, apparatus is provided for receiving an analog video signal, converting the analog video signal to a digital video signal, transmitting the digital video signal as an output, producing a recordable digital video signal from the digital video signal, and recording the recordable digital video signal on a record medium simultaneously with the transmitting of the digital video signal.
In accordance with still another embodiment of the present invention, apparatus is provided for receiving an analog video signal, converting the analog video signal to a digital video signal, shuffling blocks of the digital video signal to provide a shuffled digital video signal, orthogonally transforming the shuffled digital video signal to provide a transformed digital video signal, quantizing the transformed digital video signal to provide a quantized digital video signal, framing the quantizing digital video signal to provide a framed digital video signal, deshuffling the framed digital video signal to provide a deshuffled digital video signal, adding parity data to the deshuffled digital video signal, channel encoding the deshuffled digital video signal to provide a recordable digital video signal, recording the recordable digital video signal on a record medium, and transmitting the framed digital video signal as an output simultaneously with the recording of the recordable digital video signal.
In accordance with still a further embodiment of the present invention, apparatus is operable in a first of two recording modes for receiving a digital video signal, producing a recordable digital video signal from the digital video signal, converting the digital video signal to an analog video signal, supplying the analog video signal as an output, and recording the recordable digital video signal on a record medium simultaneously with the supplying of the analog video signal as an output. The apparatus is further operable in the second recording mode for receiving an analog video signal, converting the analog video signal to a digital video signal, producing a recordable digital video signal from the digital video signal, transmitting the digital video signal as an output, and recording the recordable digital video signal on a record medium simultaneously with the transmitting of the digital video signal.